Contents

# Contents

## Statement

###### Strøm’s theorem

Let $(X,A)$ and $(Y,B)$ be NDR-pairs. Their product in the category of topological pairs

$(X\times Y,X\times B\cup A\times Y)$

is also an NDR-pair.

## References

Last revised on September 18, 2021 at 12:25:12. See the history of this page for a list of all contributions to it.